Spectrum Analyzer Measurement Guide : Spectrum Analyzer Measurements : Setting Up Advanced Measurements
 
Setting Up Advanced Measurements
Refer to Setting Frequency Parameters to Setting Up Triggering for basic information on setting up a spectrum measurement. This section provides setup information for making swept spectrum measurements. The instrument features smart measurements that make setup easy. The following sections present brief examples demonstrating the use of these measurements.
 
MEASURE Menu
From the main menu select MEASURE > MEASUREMENT menu to select one of the desired measurements.
MEASURE Menu
 
MEASUREMENT
Select the desired measurement type from the following list:
• Spectrum: Displays the frequency domain spectrum measurement.
• Channel Power: The channel power table and channel lines are added to the measurement display. Refer to Channel Power.
• OBW: The occupied bandwidth table and channel lines are added to the measurement display. Refer to Occupied Bandwidth.
• ACP: The ACP table and channel lines are added to the measurement display. Refer to Adjacent Channel Power.
• SEM: The spectrum emissions mask table and a spectrum mask is added to the measurement display. Refer to Spectrum Emission Mask.
• PIM/Interference: Available when Option 24 is installed. The input parameters and channel measurements tables, max/min level lines, and total channel power signal indicator are added to the measurement display. Refer to PIM/Interference (Option 24).
• EMF Measurement: Available when Option 444 is installed. The EMF measurement and information tables are added to the measurement display. Refer to Electromagnetic Field (EMF) Measurements (Option 444).
• Coverage Mapping: Available when Option 431 is installed. Coverage mapping provides signal strength measurements on the instrument display and will plot color-coded signal values on an interactive map. Refer to Coverage Mapping (Option 431).
• AM/FM Audio: Available when Option 24 is installed. The AM/FM Audio provides audio demodulation capability. Refer to AM/FM Audio (Requires Option 24 or Option 509).
Also available when Option 509 is installed. Refer to AM/FM Modulation Measurement (Option 509).
• C/I: Carrier-to-Interference is the ratio of power in an RF carrier to the noise power in the channel. Carrier-to-interference ratio indicates the difference in amplitude between the desired radio frequency carrier and the noise in a portion of the spectrum. Refer to Carrier-to-Interference.
VIEW
Selects the desired measurement view from the following list:
• RF Spectrum: RF Spectrum View
• Spectrogram: When Spectrogram view is selected, a Spectrogram view is added to the display. Spectrogram is only available when the MEASUREMENT is set to Spectrum.
• All Measurements: This view is only available when AM/FM Modulation Measurement (Option 509) is installed. The measurement displays audio spectrum, RF spectrum, audio time domain and audio results.
SETUP
Opens the SETUP menu for the measurement and view selected above, except for RF SPECTRUM mode. Refer to SETUP Menu.
IQ CAPTURE
Refer to the IQ Capture/Streaming Measurement Guide (10580-00490) for more information on IQ Capture and Streaming.
MEASURE Menu (Zero Span)
MEASURE Menu (Zero Span)
 
MEASUREMENT
Selects either zero span or burst power measurement.
SETUP
Opens SETUP Menu.
Burst Average Power
Burst Average Power is the average power measured between two user defined markers positioned in the time domain.
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Burst Average Power Measurement
1. Status Panel: The status panel provides quick access to common spectrum analyzer settings.
2. Setup Menu: All burst average power measurement parameters are set via the SETUP menu
3. Burst Power Table: This table shows the values of burst average power, start and stop times.
SETUP Menu
Burst Power Setup Menu
 
BURST POWER START
Sets the burst power start time.
BURST POWER STOP
Sets the burst power stop time.
 
 
IQ CAPTURE Menu (Option 124/126)
 
IQ CAPTURE Menu
 
START/STOP CAPTURE
Touch this button to execute an IQ capture. When a capture is initiated, this button changes to STOP CAPTURE and can be touched to stop the continuous captures. Note that the captured data will still be saved unless the CANCEL SAVE button below is touched. Check the IQ status table at the bottom of the display.
CANCEL SAVE
This button appears after a capture has been initiated. Touch this button to present a dialog that allows you the choice to cancel the IQ capture save and discard the captured data, or to continue with the capture and save the data.
CAPTURE MODE
Selects the IQ capture mode:
• Single for a one-time capture to internal or external (USB) storage
• Continuous for capture to internal or external (USB) storage. Automatically initiates a new capture once the previous capture is saved.
• Streaming for continuous IQ data streaming out of the Ethernet, USB, or Data Out port (refer to IQ STREAMING Menu (Option 125/127)).
CAPTURE BW
IQ capture bandwidth is the frequency range of data to be collected for the duration of the IQ length. IQ capture bandwidth and sampling rate are linked and are selected from the same dialog.
SAMPLE RATE
Sets the IQ sampling rate of data to be collected for the duration of the IQ length. IQ sampling rate and capture bandwidth are linked and are selected from the same dialog.
CAPTURE LENGTH
Sets the duration of the waveform data capture. The maximum allowable capture period is dependent on available space on the selected storage device.
TIMESTAMPS
Toggles data collection timestamps on or off.
IQ TRIGGER
Opens the IQ TRIGGER Menu.
SAMPLE FORMAT
Sets the sampling bit format (32-bit floating decimal, 32-, 16-, 10-, or 8-bit integers).
SAVE TO FILE
Toggles automatic or manual file saving. When set to manual, touch the SAVE CAPTURE button to save the next completed IQ capture.
SAVE CAPTURE
Saves captured data to a file when SAVE TO FILE is set to Manual.
FILE NAME PREFIX
Sets the file name prefix of the capture file. Files are stored a “Captures” folder internally or to USB storage media. File naming contains the following:
prefix_year-month-day-time-##_capturetime in ns_number in scientific notation.dgz or .dgzm.
CAPTURE SIGNING
IQ files will not be signed for use with MX280005A, when toggled off.
STORAGE DEVICE
Sets the capture file save location. You can select Internal or one of the available USB ports when storage media is detected.
IQ STREAMING Menu (Option 125/127)
 
IQ STREAMING Menu
 
START STREAM
Touch this button to start IQ data streaming from the selected output port. When streaming is initiated, this button changes to STOP STREAM and can be touched to stop the stream.
CAPTURE MODE
Selects the IQ capture mode:
• Single for a one-time capture to internal or external (USB) storage (refer to SETUP Menu)
• Continuous for capture to internal or external (USB) storage (refer to SETUP Menu)
• Streaming for continuous IQ data streaming out of the Ethernet, USB, or Data Out port.
CAPTURE BW
IQ capture bandwidth is the frequency range of data to be collected for the duration of the IQ length. IQ capture bandwidth and sampling rate are linked and are selected from the same dialog.
SAMPLE RATE
Sets the IQ sampling rate of data to be collected for the duration of the IQ length. IQ sampling rate and capture bandwidth are linked and are selected from the same dialog.
TIMESTAMPS
Toggles data collection timestamps on or off (Refer to the IQ Capture/Streaming Measurement Guide, PN: 10580-00490).
IQ TRIGGER
SAMPLE FORMAT
Sets the sampling bit format (32-bit floating decimal, 32-, 16-, 10-, or 8-bit integers).
OUTPUT PORT
Selects the output port to stream the IQ data.
DATA OUTPUT FORMAT
Selects the data out format of IQC or PCIe. IQC is the default format and is intended for use with the MA25424A IQ Data Converter (Refer to the IQ Capture/Streaming Measurement Guide, PN: 10580-00490). PCIe is intended for use with the MA25101A IQ Streaming PCIe kit (refer to the MA25101A User Guide, PN: 10580-00476). Note that changing to PCIe will require the application to reload and the analyzer will be unresponsive during that time.
COMBINE FILES
IQ streams are captured in individual files that are combined once the stream stops. When this toggle is on, files will be concatenated by the instrument at the end of the stream into one file. This can be time consuming depending on the stream time. You can also save the streams as individual files and use the IQ Streaming Tool to combine the files.
Once the IQ Capture menu is accessed, the IQ CAPTURE table is displayed at the bottom of the screen.
IQ CAPTURE Table
The IQ CAPTURE table provides the following:
• STATUS: Current status of the IQ Capture. When a capture is in process, “Saving (xx%)” will be shown with an X to stop the current capture. When streaming is in process, the status will show “Streaming.”
• TRIGGER TYPE: Indicates the currently selected IQ trigger type.
• WAITING FOR TRIGGER: Indicates the capture has been started but is waiting for a trigger to initiate.
• MAX LENGTH: Indicates how long a capture can be with the current settings and available storage.
• AVAILABLE MEMORY: Indicates how much storage space is available on the target device (internal or external).
IQ TRIGGER Menu
 
Note 
Trigger commands are shared between IQ capture and zero span, so these two functions are mutually exclusive.
IQ TRIGGER Menu
 
TIMESTAMPS
toggles data collection timestamps on or off (Refer to the IQ Capture/Streaming Measurement Guide, PN: 10580-00490).
SOURCE
The SOURCE button offers several triggering options depending on which view mode the instrument is set:
• External 1 or 2: A TTL signal applied to the selected External Trigger MCX input connector causing a single capture. After the capture is complete, if mode is single, the capture will stop waiting for triggers until capture is started again. If mode is continuous, once the capture is saved, it will look for the next trigger event to initiate another capture. Any trigger made during the capturing or saving period will be ignored.
• Free Run: When trigger is free run (or manual), a trigger is only initiated when the START CAPTURE button is pressed or when a remote command is sent.
• Video: Sets the video trigger level. When RF energy is detected above that level, a capture is initiated. Note that the user must first press START CAPTURE before the analyzer will begin looking for the trigger.
LEVEL
Used when the trigger source is set to Video. Sets the video trigger level threshold that initiates a capture. The level crossing applies to rising, falling, or both edges. Use the hysteresis setting below to adjust the sensitivity of the trigger level.
DELAY
Sets the IQ trigger delay when the trigger source is not set to Free Run. IQ trigger delay can be set to positive and negative values. A negative value includes data from the specified time before the trigger event.
TIME INTERVAL
Used to set a periodic trigger event. The analyzer waits the user defined amount of time between trigger events.
SLOPE
Used when the trigger source is set to External or Video. Sets the trigger slope to rising, falling, or both. When slope is set to Both, the analyzer triggers on both the rising and falling edges. Triggering on both rising and falling edges is not available in zero span.
HYSTERESIS
Hysteresis is used to address noisy trigger signals. The hysteresis setting adjusts the sensitivity of the trigger system (the difference between the firing level and the arming level as shown in Figure: Trigger Levels and Hysteresis). A low hysteresis value sets the arming and firing levels close to each other, meaning a small signal change will cause a trigger. A large hysteresis value sets the arming and firing levels far apart, meaning a large signal change will be required to cause a trigger.
IQ CAPTURE
Returns to the SETUP Menu.
 
Trigger Levels and Hysteresis
IQ Streaming Tool
The IQ STREAMING menu allows you to concatenate an existing IQ metadata file (.dgzm) with a session of IQ data files (.dgz) that were streamed to a USB device after the stream operation is complete. The data files must all come from the same stream session.
1. Access the System menu (3-line icon in the upper left corner).
2. Select TOOLS to access the instrument tools menu, then select IQ STREAMING.
IQ Streaming Tool
1. Touch IQ METADATA FILE and then select the metadata file that you wish to concatenate with IQ data streams. All of the data stream files in the selected directory will be concatenated with the metadata file.
2. Touch the OUTPUT DIRECTORY and select the destination for the concatenated files. If desired, select Delete Source Files.
3. Select START to begin the concatenation. The progress bar will indicate relative progress.
Note 
Concatenating files can be time consuming depending on the streaming parameters and time. The process can be much faster if performed on a PC using your instrument PC application. Refer to the PC software chapter of the product’s user guide for details on using this application.